Abstract:

A new design of the air collector with the airtight and warmed casing and the absorber with the wavy surface that can be used as an additional heating element of the low-temperature heat source was developed. We established a series of generalizing dependences for finding thermal effectiveness of the collector, specifically, the influence of the components of thermal balance of the collector on the drop of temperatures in the heat carrier flow in the collector and the insolation level on heating efficiency. We obtained analytical dependences for determining the components of thermal balance of the collector, distribution of the temperature field along the absorbing panel, which made it possible to improve the mathematical model of the heat exchange process in the developed air collector. The results of the research into the air collector allowed developing the program of numerical computer calculation of the temperature field of thermal flows. It was established that application of the wavy absorbing surface of the absorber in the air heliocollector at the low level of insolation E=377 W/m2 allows increasing efficiency up to η=58.3 %, and at high energy lighting of E=1,000 W/m2, up to η=63.9 %. Performance of the collector was determined by the iterative calculation-quantitative method and made up more than 78–80 %. This is 10–20 % higher than that in flat collectors, and by 5–10 % higher than in cylindrical vacuumed collectors.The obtained results can be used in the development and improvement of the technical facilities of fruit drying, for increasing the technological and energy effectiveness of the process Author Biographies Vitaliy Boyarchuk, Lviv National Agrarian University V. Velykoho str., 1, Dublyany, Ukraine, 80381 PhD, Professor Department of Energy

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